This invention relates to the field of integrated circuit (IC) design. Specifically, it relates to a random access memory array having a plurality of micromachined electromechanical (MEM) memory cells, where each MEM memory cell includes an MEM switch and a capacitor. This invention also relates to a method of making the MEM random access memory (MEMRAM) array.
Micromachined electromechanical (MEM) switches have been developed for light-emitting display applications. U.S. Pat. No. 6,037,719 issued on Mar. 14, 2000 to Yap et al. describes such MEM switches for controlling a plurality of light-emitting devices. Each MEM switch includes a cantilever beam and a control electrode spaced therefrom to deflect the cantilever beam electrostatically in order to close or open the switch.
FIG. 2 of U.S. Pat. No. 6,037,719 illustrates a matrix circuit element of a matrix-addressed display. For each light-emitting device, two switches 22, 24 and one storage capacitor 38 are required. The two switches 22, 24 comprise the MEM switch. The first switch 22, called the driving switch, is used to control the current to drive the light-emitting device. Therefore, it determines the light emission intensity of the pixel.
The second switch 24, called the gating switch, is used to control the on/off timing of the pixel. The state of the driving switch 22 is maintained by the storage capacitor 38 coupled to the gate of the driving switch 22.
Since each matrix circuit element includes two switches, i.e., the MEM switch, and one storage capacitor, it is provided that a MEM random access memory (ME array can be designed having a plurality of MEM memory cells, where each MEM memory cell has an MEM switch and a capacitor.
It is also provided that a method can be implemented for fabricating each MEM memory cell of the MEMRAM array.
An aspect of the present invention is to provide a random access memory array having a plurality of micromachined electromechanical (MEM) memory cells, where each MEM memory cell has an MEM switch and a capacitor.
Another aspect of the present invention is to provide a method for fabricating the MEM random access memory (MEMRAM) array.
Accordingly, a MEMRAM array is disclosed which includes a plurality of MEM memory cells, where each MEM memory cell has an MEM switch and a capacitor. The MEM switch includes a contact portion configured for moving from a first position to a second position for reading out a charge stored within the capacitor or for writing the charge to the capacitor. A preferred method is also disclosed for fabricating each MEM memory cell of the MEMRAM array.